John's Jottings has MTPerlScript code to tag entries for Technorati. You can use similar code if you want to put the tags in your Atom feed instead:
<MTPerlScript>
my $keywords = "<$MTEntryKeywords$>";
my @split_keywords = split(/ /, $keywords);
my $split_keyword;
foreach $split_keyword (@split_keywords) {
print '<dc:subject>'.$split_keyword."</dc:subject>\n";
}
</MTPerlScript>
or the extra special Perl magic version:
<MTPerlScript>
print "<dc:subject>$_</dc:subject>\n" for split / /, '<MTEntryKeywords>';
</MTPerlScript>
